chain rule is g'(h(x)) h'(x) . which means..
g(x)=sin(x) [x being sin(2Pi)]
put it all into the function and you get..
which ends up giving you a 0 anyways. are you sure thats what the book is saying? lol i mean it sounds dumb to ask but this is the way i did it.. idk and i tried many times on the calculator and i keep getting zero because the derivative of t is 1.. and anything that you multiply by zero stays zero... you know??? any more info you have?